#include<stdio.h>
#include<unistd.h>
#include<signal.h>
#include<stdlib.h>

//void handler(int signo)
//{
//  printf("catch a signal : %d\n", signo);
//}

int main()
{
  //signal(2, handler);
  
  while(1){
    //printf("hello yumoz\n");
    sleep(1);
    int *p = NULL;
      *p = 20;
    //float a = 1/0;
    //raise(2);
  }
  //kill(atoi(argv[[1]]),atoi(argv[2]))
   //signal(2,handler);
   //while(1)
   //{
   // printf("hello ... \n");
   // sleep(1);
   //}
    return 0;
}
